243404261 has 2 divisors, whose sum is σ = 243404262. Its totient is φ = 243404260.

The previous prime is 243404251. The next prime is 243404267. The reversal of 243404261 is 162404342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186868900 + 56535361 = 13670^2 + 7519^2 .

It is a cyclic number.

It is not a de Polignac number, because 243404261 - 2¹⁴ = 243387877 is a prime.

It is a super-2 number, since 2×243404261² = 118491268545912242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 243404261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243404267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121702130 + 121702131.

It is an arithmetic number, because the mean of its divisors is an integer number (121702131).

Almost surely, 2^243404261 is an apocalyptic number.

It is an amenable number.

243404261 is a deficient number, since it is larger than the sum of its proper divisors (1).

243404261 is an equidigital number, since it uses as much as digits as its factorization.

243404261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 243404261 is about 15601.4185572979. The cubic root of 243404261 is about 624.3710032466.

The spelling of 243404261 in words is "two hundred forty-three million, four hundred four thousand, two hundred sixty-one".